eBay is reinvigorating its core market with a host of new experiments—many of them aimed at bringing in more goods for sale.

The latest, a program called Sell It Forward, literally has people mailing it in. Customers sign up on a website; have a bag with postage prepaid sent to them; and mail in clothes, shoes, and handbags. eBay's partner in the program, the San Francisco Bay Area branch of nonprofit Goodwill Industries, then will attempt to sell the goods.

If Goodwill thinks they're saleable and they sell within 14 days, the customer gets a 50% cut; if they do not sell, the customer gets a receipt for a donation they can use for tax purposes.

eBay has not announced the program, but we spotted an ad for it on Facebook, and a handful of beta customers have posted about it on Twitter. An eBay spokesperson did not return a request for comment.

Sell It Forward, like other recent eBay experiments, appears to be an attempt to simplify the process of listing a good for sale, which many eBay users find intimidating.

In recent months, eBay has sent trucks around to pick up goods for delivery to eBay sellers, who take a cut of the proceeds, and set up kiosks in malls where people can bring items to have a professional evaluate their value on eBay.

Such merchandise is crucial to differentiating eBay from e-commerce rivals like Amazon and Google, which generally list standardized merchandise with a barcode. Used, rare, and out-of-season goods are the eBay marketplace's specialty. But eBay depends largely on individuals to provide that merchandise.